Apparatus and method for deicing aircraft

ABSTRACT

An apparatus for deicing aircraft includes a vehicle frame, such as part of a truck, and a boom having one end mounted on the vehicle frame and a free end. A compressor unit is mounted on the boom and includes a hydraulic motor having an output and a centrifugal compressor operatively connected to the hydraulic motor output. A deicer air jet nozzle is connected at the free end of the boom and operatively coupled to the air outlet of the centrifugal compressor for receiving air and discharging the air for a deicer application.

FIELD OF THE INVENTION

The present invention relates to the field of aircraft deicing, and moreparticularly, the present invention relates to an apparatus and methodfor deicing aircraft using forced air from a compressor unit.

BACKGROUND OF THE INVENTION

Some deicing systems and methods used for deicing snow and ice-coveredaircraft surfaces use an apparatus that sprays large quantities ofdeicing fluids onto the aircraft surfaces. Typically, this has beenaccomplished by spraying a heated antifreeze fluid (e.g., a glycol andwater mixture) onto the iced surfaces of the aircraft, together with alarge quantity of compressed air. An example includes the systemdisclosed in U.S. Pat. No. 5,244,168, the disclosure which is herebyincorporated by reference in its entirety, where a nozzle mixespressurized air and deicing fluid to provide a spray pattern forapplication to the aircraft to deice the aircraft.

Other systems separate the glycol and water mixture from the compressedair and include a separate nozzle for discharging compressed air byproviding a forced air deicing system having a powerful compressed airsource. Typically, these systems include a vehicle frame, such as thechassis of a truck, having a boom with one end mounted on the vehicleframe and a free end. An operator cab is positioned at the free end ofthe boom and a deicer air jet nozzle is connected at the free end of theboom, typically mounted on the operator cab for operator control.

Many of these systems use very powerful jet engine air start units. Theair exits the nozzle at a temperature of 300° F. to 400° F. aboveambient. As a result, some of the ice and snow is melted and can migrateinto crevices on the aircraft. The aircraft acts as a heat sink becausethe large mass of the aircraft remains at subfreezing temperatures.Thus, sensitive sensors and critical trailing edge flaps may becomefrozen and ineffective.

Typically, this type of compressor is capable of 300 to 500 horsepowerand provide 300 to 400 pounds a minute of compressed air. The units arevery inefficient producing unnecessary hot air and excessive noise.Additionally, these systems are very heavy and must be positioned nearthe vehicle frame, a long distance from the operator cab carrying an airjet nozzle. As a result, long tubes must extend from the vehicle framealong the boom to the operator cab where the nozzles are located. Theselong runs from the compressor can cause thermodynamic and pneumaticdeficiencies.

Also, any system that injects fluid at high pressure into the air streamhas a drawback because the fluid could act as a cutting medium anddamage aircraft surfaces. Therefore, it is essential in some instancesto keep a great distance from the aircraft to avoid damaging theaircraft with the high pressure fluid, thus making the forced air systemineffective.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anapparatus and method for deicing aircraft where a compressor unit,including any motor driving the compressor, can be mounted on the boom,proximate to a deicer air jet nozzle.

It is still another object of the present invention to provide anapparatus and method for deicing aircraft that uses forced air dischargethat is efficient and uses a compressor unit that is lightweight, butgenerates an air discharge from a deicer air jet nozzle that isappropriate for deicing aircraft under frigid conditions, but also doesnot discharge at temperatures substantially above ambient temperature.

In accordance with the present invention, an apparatus and method fordeicing aircraft now allows a compressor unit to be mounted on thevehicle boom by the use of a centrifugal compressor, such as the type ofcompressor commonly used when supercharging internal combustion engines.This type of compressor is directly connected to a motor output, whichin a preferred aspect of the invention is a hydraulic motor via atransmission, such as a belt, and in a preferred aspect, a drive gearunit. The centrifugal compressor includes an impeller and outlet as isnormal with many of the superchargers used in automobile vehicleengines. The apparatus includes a vehicle frame and a boom having oneend mounted on the vehicle frame and a free end. The compressor unit ismounted on the boom proximate to the free end and a deicer air jetnozzle is connected at the free end of the boom and operatively coupledto the air outlet of the centrifugal compressor for receiving air anddischarging the air for a deicer application.

A hydraulic pump is mounted on the vehicle frame and hydraulic feedlines extend from the hydraulic pump along the boom to the hydraulicmotor for supplying hydraulic fluid under pressure to the hydraulicmotor. The vehicle frame can typically include a vehicle engine, such asnormal with a truck. A transmission is driven from the vehicle engineand interconnects the hydraulic pump for supplying power to thehydraulic motor.

A drive gear unit is operatively connected between the centrifugalcompressor and the hydraulic motor for stepping up the revolutions perminute of the centrifugal compressor relative to the output of thehydraulic motor. The drive gear unit further comprises an input spurgear driven from the hydraulic motor and an output spur gear driving thecentrifugal compressor. The input spur gear and output spur gear defineabout a 2:1 to about 4:1 gear ratio. The deicer air jet nozzle definesan axisymmetric contour having a converging portion. An example of suchan air jet nozzle is disclosed in U.S. Pat. No. 5,755,404, thedisclosure which is hereby incorporated by reference in its entirety.

Typically, a fluid nozzle is mounted on the deicer air jet nozzle. Asource of deicing fluid could be mounted at the vehicle frame and asupply tube interconnects the source of deicing fluid in the fluidnozzle. A pump is operatively connected to the source and supply tubeand pumps deicing fluid from the source of deicing fluid through thesupply tube and fluid nozzle. Typically, if an aircraft contains muchice, the deicing fluid would be placed on the ice to aid in melting theice. A centrifugal pump can typically inject deicing fluid into the airstream at 100 to 200 PSIG. Any greater pressure could create problemswith aircraft damage.

A method aspect is also disclosed and includes the steps of compressingair within a centrifugal compressor located on a vehicle boom by drivinga motor coupled to the centrifugal compressor and discharging the airfrom a deicer air jet nozzle attached to the end of the vehicle boomsuch that air is forced outward from the deicer air jet nozzle at about100 pounds per minute.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome apparent from the detailed description of the invention whichfollows, when considered in light of the accompanying drawings in which:

FIG. 1 illustrates a deicing apparatus of the present invention with atruck containing a boom and a deicer assembly positioned on the boom forproviding compressed air to the deicer air jet nozzle that is mounted atan operator cab positioned at the free end of the boom.

FIG. 2 is an enlarged isometric view of the operator cab and the deicerair jet nozzle and a fluid nozzle mounted at the operator cab at thefree end of the boom.

FIGS. 3A through 3C illustrate a deicer assembly of the presentinvention contained in a housing and mounted on the boom.

FIG. 4 is an exploded isometric view of a compressor unit of the presentinvention and showing the hydraulic motor, centrifugal compressor anddrive gear unit.

FIG. 5 is a schematic drawing showing the centrifugal compressor fixedto a compressor mounting frame and a mounting bracket that secures thecompressor mounting frame to the boom of a vehicle.

FIG. 6 is a schematic view of a centrifugal compressor that can be usedwith the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout.

The present invention is advantageous because it now provides for anefficient apparatus and method for deicing aircraft without usingexpensive and powerful compressors and motors that must be positioned ona vehicle frame and far from any air nozzles. A deicer assembly of thepresent invention includes a centrifugal compressor and motor, which arelightweight and can be mounted on the boom connected to a vehicle frame,and thus, located proximate to an operator cab positioned at the freeend of the boom. The motor is preferably a hydraulic motor. Thecompressor and hydraulic motor can be placed on the boom so that onlyhydraulic hoses from the hydraulic pump driven by a vehicle engine orseparate auxiliary engine should be threaded or mounted along the boom,thus reducing the weight applied on the boom. Additionally, the use ofthe deicer air jet nozzle having an axisymmetric contour, such asdisclosed in the above-identified and incorporated by reference '404patent, allows the compressor to work in conjunction with the nozzle toprovide a source of air at about 80 to 120 pounds per minute, whichexits typically at no more than 15° to 30° F. above ambient in typicalapplications. Also, the pressure is discharged from about 13 to 14 PSIG,above atmospheric pressure.

Referring now to FIG. 1, there is illustrated a truck 10, which includesa vehicle cab 12 and vehicle engine 14 under the vehicle cab. Thevehicle cab 12 and engine 14 are mounted on the vehicle frame 16. A boom18 has one end pivotally mounted on the vehicle frame 16 in such amanner to allow both vertical and circular movement of the boom. Acontrol panel 20 is located in the vehicle cab 12 and actuates the boom18 by means of a corresponding hydraulic assembly 21 to move the boom ina desired vertical direction and turn the boom in the desired angularposition. Naturally, the boom 18 could be located on a vehicle frame 16,such as a trailer or platform, that might extend outward from the rearof a large truck.

As shown further in FIG. 1, an operator cab 22 is positioned at the freeend 24 of the boom. An operator sits in the operator cab 22 to operate adeicer air jet nozzle 26, which in turn, is positioned at the free endof the boom, and typically at the end of the boom or directly on theoperator cab. FIG. 1 also illustrates greater details of an air jetnozzle mounted on the end of the boom, as will be explained in detailbelow. A deicer assembly 28 is also mounted on the boom and, inaccordance with the present invention, is located proximate to thedeicer air jet nozzle 26. Thus, the present invention is different frommany prior art devices, where compressors and any large powerful motorsdriving any compressors were located on the vehicle frame due to thelarge and typically inefficient components used in these systems.

Referring now more particularly to FIGS. 4-6, details of the deicerassembly 28 are illustrated. A compressor mounting frame 30 has amounting mechanism 32, in the form of brackets, positioned on thecompressor mounting frame 30, which secure the compressor mounting frame30 to the boom as shown in FIG. 5. The compressor mounting frame can beformed as a rigid L-shaped, metal support plate. The mounting rackets 32can be formed as flexible metal straps (FIGS. 3A-3C). A centrifugalcompressor 34 is fixed to the compressor mounting frame 30. As shown inFIGS. 4 and 6, the centrifugal compressor 34 is designed similar to thecentrifugal compressors used as in supercharger systems on manyautomobiles. One design that has been found efficient for the presentinvention is a centrifugal compressor used as a supercharger under thetradename "V4X Supercharger" as manufactured by Vortech Engineering,Inc. of Morpark, Calif., and disclosed in greater detail in U.S. Pat.No. 5,224,459, the disclosure which is hereby incorporated by referencein its entirety.

The centrifugal compressor 34 includes a rotating impeller 36 (FIG. 6)that is mounted on internal bearings (not shown) at the air intake 36a.The rotating impeller 36 includes an internal gear that is connected toanother internal gear and power input shaft 38, such that the speed ofthe impeller can be increased by the internal gear ratio. Typically, theinternal gears can be a helically designed set of gears with analuminum, backward curved impeller 36. The compressor can typically havean air pressure of 29 PSIG, and reaches a 1700 cubic feet per minuteflow rate.

A drive gear unit 40 is mounted on the centrifugal compressor byappropriate fasteners 42, such as bolts, as illustrated. The drive gearunit 40 includes an output spur gear 44 connected to the input shaft 38of the centrifugal compressor 34. The output spur gear 44 is designed asa pinion gear that meshes with an input spur gear 46. Both the input andoutput spur gears 44,46 are contained in a gear case box 48 having anappropriate gear case cover 50. A power shaft is connected on a hub 54near the central portion of the larger input spur gear.

A hydraulic motor 56, such as a standard industrial hydraulic motor soldunder the series F12 unit, manufactured by VOAC Hydraulics Division,S-461 82, Trollhatton, Sweden, of Parker Hydraulics, is mounted on thedrive gear unit 40 via bolts 57 and has an output 58 that connects tothe hub 54 located on input spur gear 46. The series F12 is a hydraulicmotor that is a bent axis, fixed displacement heavy duty motor. It canbe used for both open and closed loop applications. The motor has aunique spherical piston design and can typically run at high shaftspeeds. It has operating pressures to 7000 psi, and provides for highoutput power capability. A 40° angle between shaft and cylinder barrelallows for a compact, lightweight motor. It is evident in FIG. 5 thatthe centrifugal compressor 34, drive gear unit 40 and hydraulic motor 56form one complete compressor unit that is secured by the compressormounting frame 30 and mounting brackets 32 to the boom 18. Naturally,other motor designs could be used as long as the motor designs, whetherelectrical or hydraulic, meet the design parameters necessary fordriving the compressor.

In a preferred aspect of the present invention, a hydraulic pump 60 ismounted on the vehicle frame and typically operates by a cam or othertransmission system 62 driven from the vehicle engine 14 or auxiliaryengine. However, other locations and pump transmissions could be useddepending on the vehicle design and type of components used in thepresent invention. Hydraulic lines 64 extend between the hydraulic pump60 and the hydraulic motor 56 as shown in FIGS. 1 and 3A-3C, whichprovides the hydraulic fluid power necessary for driving the hydraulicmotor. An air cleaner 66 is mounted at the impeller air intake area 68of the centrifugal compressor to filter any air entering the centrifugalcompressor.

Referring now to FIG. 2, further details of the operator cab and thedeicer air jet nozzle 26 are illustrated and described.

In one preferred aspect of the present invention, the deicer air jetnozzle 26 is the type of nozzle disclosed in the above-identified andincorporated by reference '404 patent. The nozzle 26 typically uses atubular structure 70 having rigid conduit segments 72 and a stationarysupport 74. Typically, the nozzle includes an axisymmetric contourportion 76 and a converging portion 78 at the nozzle. An air supply tube80 extends rearward to the air outlet 37 at the impeller 36 of thecentrifugal compressor. As illustrated, a fluid nozzle 82 is positionedon the deicer air jet nozzle 26 and includes a fluid feed tube 84 thatextends along the boom 18 to a reservoir of deicer fluid, illustratedgenerally at 85, typically formed from a glycol and water mixture. Acentrifugal fluid pump 86 is operated by an operator in the operator cabto energize the pump and force fluid through the supply tube and throughthe fluid nozzle.

In operation, an operator in the operator cab can move the operator cabinto a desired position and angle adjacent the aircraft. If a largeamount of ice is located on a wing, the operator can energize the fluidpump 86 to pump fluid from the fluid reservoir 85 through the fluidnozzle 82 onto the wing of a airplane to provide initial deicing of anythick ice positioned on the wing. Preferably, no fluid is used, only ajet of air is discharged if no ice is present. After the glycol/watermixture has been placed onto the wing (if used), the operator energizesthe hydraulic pump directly from the vehicle engine to drive thehydraulic motor and force the centrifugal compressor into operation bymeans of the hydraulic motor. About 80 to 120 pounds of air per minuteare discharged through the deicer air jet nozzle at about 13 to 14 PSIG,and about 15° to 30° F. above ambient temperature with the use of thenozzle described above.

Naturally, the amount of air discharged through the deicer air jetnozzle 26 can vary depending on the end use needs. Because thecentrifugal compressor 34 and the associated hydraulic motor and drivegear unit are positioned on the boom, and proximate to the deicer airjet nozzle, more efficient use is made of the compressor. Additionally,air with high pressure deicing fluid injected is not used as in someprior art systems, which under certain conditions, could create acutting fluid. When injected fluid is needed, the injected deicing fluidused is at 100 to 200 PSIG pressure and cannot damage the aircraft.Also, an efficient use is made of a centrifugal compressor, drive gearunit and hydraulic motor, such that horsepower requirements for deicingare reduced. Thus, the centrifugal compressor and hydraulic motor can bemounted on the boom, as compared to many prior art devices where any aircompressor and associated drive units were mounted on the vehicle frame.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is to be understood that the invention is not to belimited to the specific embodiments disclosed, and that themodifications and embodiments are intended to be included within thescope of the dependent claims.

That which is claimed is:
 1. An apparatus for deicing aircraftcomprising:a vehicle frame; a boom having an end supported by thevehicle frame and a free end; a compressor unit mounted on the boom,said compressor unit comprising:a hydraulic motor having an output, anda centrifugal compressor operatively connected to the hydraulic motoroutput and having an impeller and an air outlet; and a deicer air jetnozzle connected at the free end of the boom and operatively coupled tothe air outlet of the centrifugal compressor for receiving air anddischarging the air for a deicer application.
 2. An apparatus accordingto claim 1, and further comprising a hydraulic pump mounted on thevehicle frame and hydraulic feed lines extending from said hydraulicpump along said boom to said hydraulic motor for supplying hydraulicfluid under pressure to said hydraulic motor.
 3. An apparatus accordingto claim 2, wherein said vehicle frame includes a vehicle engine, and atransmission driven from said vehicle engine and interconnecting saidhydraulic pump for supplying power to said hydraulic pump.
 4. Anapparatus according to claim 1, and further comprising a drive gear unitoperatively connected between said centrifugal compressor and saidhydraulic motor for stepping up the revolutions per minute of saidcentrifugal compressor relative to the output of said hydraulic motor.5. An apparatus according to claim 4, wherein said drive gear unitfurther comprises an input spur gear driven from said hydraulic motorand an output spur gear driving said centrifugal compressor.
 6. Anapparatus according to claim 5, wherein input spur gear and output spurgear defines about a 2:1 to about 4:1 gear ratio.
 7. An apparatusaccording to claim 1, wherein said deicer air jet nozzle defines anaxisymmetric contour having a converging portion.
 8. An apparatusaccording to claim 1, and further comprising a fluid nozzle mounted onsaid deicer air jet nozzle, a source of deicing fluid, a supply tubeinterconnecting said source of deicing fluid and fluid nozzle, and acentrifugal fluid pump for pumping deicing fluid from the source ofdeicing fluid and through the supply tube and fluid nozzle.
 9. Anapparatus according to claim 1, wherein said centrifugal pump forces airthrough said deicer air jet nozzle at about 80 to about 100 pounds perminute.
 10. An apparatus for deicing aircraft comprising:a vehicleframe; a boom having an end mounted on the vehicle frame and a free end;a compressor unit supported by the boom, said compressor unitcomprising:a motor having an output, and a centrifugal compressoroperatively connected to the motor output and having an impeller and anair outlet; and a deicer air jet nozzle connected at the free end of theboom and operatively coupled to the air outlet of the centrifugalcompressor for receiving air and discharging the air for a deicerapplication.
 11. An apparatus according to claim 10, wherein saidcentrifugal compressor forces air through said deicer air jet nozzle atabout 80 to 100 pounds per minute.
 12. An apparatus according to claim10, wherein said motor comprises a hydraulic motor, and furtherincluding a hydraulic pump and hydraulic feed lines extending from saidhydraulic pump to said hydraulic motor.
 13. An apparatus according toclaim 12, wherein said hydraulic pump is mounted on said vehicle frame,and said hydraulic feed lines extend from said hydraulic pump along saidboom to said hydraulic motor for supplying hydraulic fluid underpressure to said hydraulic motor.
 14. An apparatus according to claim13, and further comprising a hydraulic pump mounted on the vehicle frameand hydraulic feed lines extending from said hydraulic pump along saidboom to said hydraulic motor for supplying hydraulic fluid underpressure to said hydraulic pump.
 15. An apparatus according to claim 14,including an engine mounted on said vehicle frame, and a transmissiondriven from said vehicle engine and interconnecting said hydraulic pumpfor supplying power to said hydraulic pump.
 16. An apparatus accordingto claim 10, wherein said deicer air jet nozzle defines an axisymmetriccontour having a converging portion.
 17. An apparatus according to claim10, and further comprising a fluid nozzle mounted on said deicer air jetnozzle, a source of deicing fluid, a supply tube interconnecting saidsource of deicing fluid and fluid nozzle, and a centrifugal fluid pumpfor pumping deicing fluid from the source of deicing fluid and throughthe supply tube and fluid nozzle.
 18. An apparatus for deicing aircraftcomprising:a vehicle frame; a boom having an end mounted on the vehicleframe and a free end; a compressor unit supported by the boom, saidcompressor unit comprising:a motor having an output, an input spur gearconnected to the motor output, an output spur gear meshing with theinput spur gear; a centrifugal compressor operatively connected to theoutput spur gear and having an impeller and an air outlet; and a deicerair jet nozzle connected at the free end of the boom and operativelycoupled to the air outlet of the centrifugal compressor for receivingair and discharging the air for a deicer application.
 19. An apparatusaccording to claim 18, wherein said centrifugal compressor forces airthrough said deicer air jet nozzle at about 100 pounds per minute. 20.An apparatus according to claim 18, wherein said motor comprises ahydraulic motor, and further including a hydraulic pump and hydraulicfeed lines extending from said hydraulic pump to said hydraulic motor.21. An apparatus according to claim 20, wherein said hydraulic pump ismounted on said vehicle frame, and said hydraulic feed lines extend fromsaid hydraulic pump along said boom to said hydraulic motor forsupplying hydraulic fluid under pressure to said hydraulic motor.
 22. Anapparatus according to claim 21, wherein said vehicle frame includes avehicle engine, and a transmission driven from said vehicle engine andinterconnecting said hydraulic pump for supplying power to saidhydraulic pump.
 23. An apparatus according to claim 18, wherein saiddeicer air jet nozzle defines an axisymmetric contour having aconverging portion.
 24. An apparatus according to claim 18, and furthercomprising a fluid nozzle mounted on said deicer air jet nozzle, asource of deicing fluid, a supply tube interconnecting said source ofdeicing fluid and fluid nozzle, and a centrifugal fluid pump for pumpingdeicing fluid from the source of deicing fluid and through the supplytube and fluid nozzle.
 25. A deicer assembly comprising:a compressormounting frame; a mounting mechanism secured to the frame for attachingthe compressor mounting frame to a boom of a vehicle; a centrifugalcompressor mounted on the compressor mounting frame, said centrifugalcompressor having an input shaft, an impeller and an air outlet; a drivegear unit mounted on the centrifugal compressor, and having an inputspur gear and output spur gear connected to the input shaft of thecentrifugal compressor; and a hydraulic motor mounted on the drive gearunit and having an output connected to the input spur gear.
 26. Anapparatus according to claim 25, wherein said drive gear unit defines athree to four gear ratio.
 27. A method for deicing aircraft comprisingthe steps of:compressing air within a centrifugal compressor supportedby a vehicle boom by driving a motor coupled to the centrifugalcompressor; and discharging the air from a deicer air jet nozzleattached to the end of the vehicle boom such that air is forced outwardfrom the deicer air jet nozzle at about 100 pounds per minute.
 28. Amethod according to claim 27, wherein the air is discharged from thedeicer air jet nozzle at about 10 to about 13 pounds per square inch.29. A method according to claim 27, wherein the air is dischargedthrough air jet nozzle that defines an axisymmetric contour having aconverging portion.
 30. A method according to claim 27, and furthercomprising the step of hydraulically driving the motor, wherein themotor comprises a hydraulic motor.
 31. A method according to claim 30,and further comprising the step of driving the hydraulic motor by ahydraulic pump located on a vehicle frame.
 32. A method according toclaim 31, and further comprising the step of operating the hydraulicpump from directly from the engine used for driving the vehicle.
 33. Amethod according to claim 30, and further comprising the step ofstepping up the revolutions per minute of the centrifugal compressorrelative to the output of the motor by a gear drive coupled between thecentrifugal compressor and the motor.
 34. A method according to claim27, and further comprising the step of discharging the air from thenozzle at above about 15 degrees above ambient temperature.